1. Field of the Invention
The present invention relates to a bulb socket and, more particularly, to a socket for a wedge base bulb (no-cap bulb) for use in a lighting device which is employed in an automobile or the like.
2. Related Art
FIG. 13 shows a conventional bulb socket for a wedge base bulb. The conventional bulb socket comprises a socket main body 2 which is formed of synthetic resin and includes a forwardly opening bulb insertion opening 3 into which a wedge base bulb 8 can be inserted. A pair of elastic hooks 4 are provided in the insertion opening for retaining a synthetic resin base 8a of the inserted wedge base bulb 8. That is, by inserting the wedge base bulb 8 into the bulb insertion opening 3 from above, or by pulling the wedge base bulb 8 upwardly out of the bulb insertion opening 3, the bulb 8 can be mounted into or removed from the bulb socket by means of the flexibility of the elastic hooks 4.
Also, in the bulb insertion opening 3, there is stored a contact terminal (not shown) which is electrically connected to a plurality of energizing wires 5. In a state where the base 8a is engaged with the elastic hooks 4 so that the wedge base bulb 8 is secured in the bulb insertion opening 3, the base 8a of the bulb 8 is held between contact terminals provided within the socket main body 2, so that a lead wire 9 exposed to the base 8a can be electrically contacted with the contact terminals within the socket main body 2.
Further, on the outer periphery of the socket main body 2, there are provided a plurality of securing projections 6 which can be engaged in a bayonet-like manner in a socket mounting hole formed in a lamp body serving as a lighting device forming member, and a flange 7 which cooperates with the securing projections 6. Thus, if the securing projections 6 are matched to the socket mounting hole and the socket main body 2 is pushed in and, at the same time, if the thus pushed-in socket main body is rotated a given amount along the peripheral edge portion of the mounting hole, then the peripheral edge portion of the mounting hole can be held and fixed by the securing projections 6 and flange 7.
However, in the above-mentioned conventional bulb socket, in order to positively retain the flat outside surface of the base 8a, the elastic hooks 4 are arranged in parallel along a wide bulb insertion opening forming wall 2a. Due to this, there is produced a certain clearance between the parallel arranged elastic hooks 4 and the adjacent wall 2a. As a result of this, when the bulb 8 is inserted into the bulb insertion opening 3, the leading end portion of the base 8a can be inadvertently inserted into this clearance. As a result, it is difficult to insert the bulb 8 into the bulb insertion opening 3 smoothly, or if the bulb 8 is pushed in forcibly, there is a possibility that the elastic hooks 4 may be broken.